Coaxial probes have been used in fluid level sensors to measure fluid levels in closed tanks, open tanks, reservoirs, and other environments. Radio frequency (“RF”) electronics can be attached with the signal passing into the sensor's inner conductor while the outer conductor is connected to ground. These sensors are sometime referred to as guided wave radar level sensors or microwave level sensors. To measure a fluid level, the probe can be positioned vertically at a known height with one end immersed in a fluid. The fluid flows around and into the probe. Activating the RF electronics and reading the sensor output indicates the portion of the probe length that is immersed.
The coaxial probes have an inner rod, an outer shell, and a spacer that centers the rod within the shell. The spacers cannot be solid because solid spacers prevent the fluid from flowing up the inside of the probe between the inner rod and the outer shell. Currently used coaxial probes use specially shaped spacers such as stars or disks cut along a chord or two. Assembling coaxial probes with these specially shaped spacers requires that the spacer be slid down the length of the inner rod. Such assembly can be difficult, especially in the field. Systems and methods for more easily assembled coaxial probes are needed.